In some cases, design requirements other than the optimization of a specific bonded joint dictate that the net stiffnesses on each side of a bonded joint need to be unbalanced.
In other instances, thermally dissimilar materials must be bonded together.
Such situations accentuate the adhesive strain concentrations at one end of the joint, thereby reducing the average adhesive failing stress for intermediate and long overlaps.
There are three mathematically distinct cases:
(1) fully elastic adhesive throughout,
(2) adhesive strained into the plastic state at one end only, and
(3) plastic adhesive behavior at both ends of the joint and the associated special case of fully-plastic behavior throughout the joint.
The implemented formula consider a fully elastic adhesive.
ADHESIVE-BONDED DOUBLE-LAP JOINTS